1. Field of the Invention
The present invention relates to a liquid droplet ejection apparatus including an ejection defect test unit for inspecting the ejection defect of a functional liquid droplet ejection head that ejects functional liquid onto a workpiece, a method for manufacturing an electro-optic device, an electro-optic device, and an electronic equipment.
2. Description of the Related Art
There is known a liquid droplet ejection apparatus which is used to manufacture a variety of products (e.g., a color filter of a liquid crystal display device) by a liquid droplet ejection method using a functional liquid droplet ejection head. The liquid droplet ejection apparatus includes an X-axis direction moving mechanism which moves a substrate transport table (set table), on which a substrate (workpiece) is set, in the X-axis direction and a Y-axis direction moving mechanism which moves a head unit, on which the functional liquid droplet ejection head is mounted, in the Y-axis direction. The area where the moving area of the head unit and the moving area of the substrate transport table overlap is a liquid droplet ejection area where drawing (picturing) can be carried out on the substrate. By driving the ejection of the functional liquid droplet ejection head while relatively moving the head unit and the substrate, the liquid droplet ejection apparatus can draw a predetermined drawing pattern on the substrate located in the liquid droplet ejection area.
The liquid droplet ejection apparatus also includes a dot defect detection unit for inspecting a nozzle clog of the functional liquid droplet ejection head. The dot defect detection unit is located under the moving area of the head unit and at a position shifted from the moving area of the substrate transport table. The dot defect detection unit includes a light receiving unit for causing each ejection nozzle of the functional liquid droplet ejection head to eject functional droplets for testing to optically detect the presence of the functional liquid droplet and a test liquid receiving unit for receiving the functional droplets for testing. When the dot defect inspection is carried out, the head unit is moved to a position immediately above the test liquid receiving unit. The ejection of the functional liquid droplet ejection head is then driven so that each nozzle of the functional liquid droplet ejection head ejects a functional droplet for testing onto the test liquid receiving unit and the light receiving unit detects the presence of the functional liquid droplet ejected from each nozzle (see, for example, JP-A-2004-202325).
To increase the manufacturing yield of the drawing, it is desirable that the dot defect detecting operation is regularly carried out in addition to being carried out at the start-up time of the liquid droplet ejection apparatus. That is, it is desirable that the dot defect detecting operation is carried out when a workpiece is mounted on the set table and dismounted from the set table so that the proper ejection of functional liquid from the functional liquid droplet ejection head is inspected before starting the next drawing operation. However, in the known liquid droplet ejection apparatuses, the dot defect detection unit is located at a position shifted from the moving area of the substrate transport table. Therefore, the known liquid droplet ejection apparatuses need to drive the Y-axis direction moving mechanism to move the head unit in the drawing area to the dot defect detection unit when detecting the dot defect in an interval between the drawing operations on a workpiece. The known liquid droplet ejection apparatuses also need to drive the Y-axis direction moving mechanism again to move the head unit to the drawing area after the dot defect detection. Accordingly, in the known liquid droplet ejection apparatuses, a cycle time for the dot defect detection is increased, and therefore, the efficiency of the drawing operation on the workpiece deteriorates.